Networks of connected devices for exchanging data and sharing hardware resources can be built up not only for computers but also for consumer electronic devices. The separate devices are called nodes of the network. Networks can be classified as being based on either client-server or peer-to-peer (P2P) architectures, where a node is also referred to as a peer. While in client-server architectures each node is defined to be either client or server, peers in P2P networks include both functionalities, server and client, and can provide services or resources to other nodes in the network or use services or resources provided by other nodes in the network.
P2P networks are usually not restricted to any special applications or underlying network topologies, but can be understood as a set of nodes, or peers, which rely on certain sets of specific protocols. It is characteristic for a P2P network that the peers communicate directly with other peers, so that no central network organization is required. P2P networks may support that peers can be connected to the network or disconnected from the network at any time.
The mentioned P2P protocols are required for basic network organization, such as e.g. discovery of other connected peers, offering of services or resources to other peers (advertising), or understanding other peers' advertising messages. Also, there are protocols that enable a group of peers to cooperate, and thus form a peer-group. A method for building a home network as a peer-group based on such P2P techniques is described e.g. in the European patent application EP02027122. General P2P networks and mechanisms are in a detailed manner published e.g. in WO 02/057917.
Quality of Service (QoS) is a networking term specifying the characteristics and quality of a connection between two distinct points in a network, e.g. a guaranteed throughput level being the amount of data transferred from one place to another in a specified amount of time, a minimum bandwidth or a maximum delay of transmitted data. Usually various QoS classes are defined and network connections are categorized by the QoS class they may provide. Different network infrastructures utilize different strategies and protocols. E.g. the IEEE 1394 protocol is developed for audio-visual (AV) data handling with guaranteed throughput, while e.g. the Ethernet network uses a simple “best effort” approach. To achieve QoS functionality in Ethernet networks there exist models like assigning priorities or allocating network resources for a data transfer.
However, the known QoS strategies require special knowledge of the currently used physical network. Currently known QoS management approaches for home networks require considering QoS at all layers, also at the network layer.